Performance Improvement of Time-Differenced Carrier Phase Measurement-Based Integrated GPS/INS Considering Noise Correlation

In this study, we combined a time-differenced carrier phase (TDCP)-based global positioning system (GPS) with an inertial navigation system (INS) to form an integrated system that appropriately considers noise correlation. The TDCP-based navigation system can determine positions precisely based on high-quality carrier phase measurements without difficulty resolving integer ambiguity. Because the TDCP system contains current and previous information that violate the format of the conventional Kalman filter, a delayed state filter that considers the correlation between process and measurement noise is utilized to improve the accuracy and reliability of the TDCP-based GPS/INS. The results of a dynamic simulation and an experiment conducted to verify the efficacy of the proposed system indicate that it can achieve performance improvements of up to 70% and 60%, respectively, compared to the conventional algorithm.

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Indoor Carrier Phase Positioning Technology Based on OFDM System

Sensors ◽

10.3390/s21206731 ◽

2021 ◽

Vol 21 (20) ◽

pp. 6731

Author(s):

Zhenyu Zhang ◽

Shaoli Kang ◽

Xiang Zhang

Keyword(s):

High Resolution ◽

Ambiguity Resolution ◽

Carrier Phase ◽

Phase Measurement ◽

Research Direction ◽

Global Navigation Satellite Systems ◽

Integer Ambiguity ◽

Ofdm Systems ◽

Carrier Phase Measurement ◽

Phase Measurements

Carrier phase measurement is a ranging technique that uses the receiver to determine the phase difference between the received signal and the transmitted signal. Carrier phase ranging has a high resolution; thus, it is an important research direction for high precision positioning. It is widely used in global navigation satellite systems (GNSS) systems but is not yet commonly used inwireless orthogonal frequency division multiplex (OFDM) systems. Applying carrier phase technology to OFDM systems can significantly improve positioning accuracy. Like GNSS carrier phase positioning, using the OFDM carrier phase for positioning has the following two problems. First, multipath and non-line-of-sight (NLOS) propagation have severe effects on carrier phase measurements. Secondly, ambiguity resolution is also a primary issue in the carrier phase positioning. This paper presents a ranging scheme based on the carrier phase in a multipath environment. Moreover, an algorithm based on the extended Kalman filter (EKF) is developed for fast integer ambiguity resolution and NLOS error mitigation. The simulation results show that the EKF algorithm proposed in this paper solves the integer ambiguity quickly. Further, the high-resolution carrier phase measurements combined with the accurately estimated integer ambiguity lead to less than 30-centimeter positioning error for 90% of the terminals. In conclusion, the presented methods gain excellent performance, even when NLOS error occur.

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Low Cost AHRS Aids GPS Attitude Navigation System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.536-537.748 ◽

2014 ◽

Vol 536-537 ◽

pp. 748-755

Author(s):

Tong Yue Gao ◽

Hai Lang Ge

Keyword(s):

Navigation System ◽

Carrier Phase ◽

Phase Measurement ◽

Low Cost ◽

Integer Ambiguity ◽

Baseline Length ◽

Carrier Phase Measurement ◽

Basic Model ◽

Aircraft Type ◽

Gps System

Recently, the SUAV has become the research focus at home and abroad. There is a new aircraft type: double ducted tilting Subminiature UAV system, this paper put forward a new attitude navigation system:AHRS-based low-cost GPS carrier phase orientation Navigation System. AHRS aids GPS fastly fix the attitude.This article proposed application the constraint solving the ambiguity basic model, which is based on the double differential equations of the carrier phase measurement. Then we use baseline length and the inaccurate attitude angle constraint to solver integer ambiguity. By the static experimental results show that this method is fast, effective, the AHRS-GPS system can provide high accuracy navigation for SUAV.

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Integration and Simulations of INS/GNSS System using the Approach of Carrier Phase Measurements

IAES International Journal of Robotics and Automation (IJRA) ◽

10.11591/ijra.v4i4.pp243-253 ◽

2015 ◽

Vol 4 (4) ◽

pp. 243

Author(s):

Khan Badshah ◽

Qin Yongyuan

Keyword(s):

Kalman Filtering ◽

Carrier Phase ◽

Closed Loop ◽

Position Estimation ◽

Integrated System ◽

Integer Ambiguity ◽

Font Size ◽

Phase Measurements ◽

Simulation Results ◽

Lever Arm Effect

This paper discusses the techniques of attitude, velocity ad position estimation from GNSS carrier phase measurements, and investigates the performance of the lower precision MEMS-based INS/GNSS system based on carrier phase measurements. Double differenced carrier phase measurements provide more accurate velocity and position estimation compared to code and Doppler measurements. However, integer ambiguity is required to be removed for precise positioning. Multiples antennae approach is used to derive the attitude information from carrier phase measurements in order to control the large initial misalignment angles for initialization of the integration process or to utilize during benign dynamics. Lever arm effect is considered to compensate for the separation of GNSS antenna and IMU location. The derived three GNSS observables are used to correct the INS through optimal Kalman filtering in a closed loop. Simulation results indicates the effectiveness of the integrated system for airborne as well as for land navigation vehicles. <div id="_mcePaste" class="mcePaste" style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow: hidden;">This paper discusses the techniques of attitude, velocity ad position estimation from GNSS carrier phase measurements, and investigates the performance of the lower precision MEMS based INS/GNSS system based on carrier phase measurements. Double differenced carrier phase measurements provide more accurate velocity and position estimation compared to code and Doppler measurements. However, integer ambiguity is required to be removed for precise positioning. Multiples antennae approach is used to derive the attitude information from carrier phase measurements in order to control the large initial misalignment angles for initialization of the integration process or to utilize during benign dynamics. Lever arm effect is considered to compensate for the separation of GNSS antenna and IMU location. The derived three GNSS observables are used to correct the INS through optimal Kalman filtering in a closed loop. Simulation results indicates the effectiveness of the integrated system for airborne as well as for land navigation vehicles. </div>

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Robust INS/SFPPP-BDS tightly coupled navigation algorithm with adaptive cycle slip compensation model

Journal of Algorithms & Computational Technology ◽

10.1177/1748301819833044 ◽

2019 ◽

Vol 13 ◽

pp. 174830181983304

Author(s):

Hangshuai Ma ◽

Rong Wang ◽

Zhi Xiong ◽

Jianye Liu ◽

Chuanyi Li

Keyword(s):

Navigation System ◽

Carrier Phase ◽

Low Cost ◽

Integrated System ◽

Single Frequency ◽

Cycle Slip ◽

Phase Measurements ◽

Satellite Navigation System ◽

Tightly Coupled ◽

Robust Adaptive

The application of Beidou Satellite Navigation System (BDS) is developing rapidly. To satisfy the increasing demand for positioning performance, single-frequency precise point positioning (SFPPP) has been a focus in recent years. By introducing the SFPPP technique into the INS/BDS integrated system, higher navigation accuracy can be obtained. Cycle slip, which is caused by signal blockage during the measurement of the carrier phase, is a challenge for SFPPP application. In the INS/SFPPP-BDS integrated system, cycle slip can cause serious bias in BDS carrier phase measurements. In this paper, a new INS/SFBDS-PPP tightly coupled navigation system and a robust adaptive filtering method are proposed. Using a low-cost single-frequency receiver integrated with INS, an observation model was built based on the pseudo range and carrier phase by PPP preprocessing. The cycle slip was introduced into the state vector to improve the estimation precision. The test statistics, comprising the innovation and its covariance, were used to estimate the time at which cycle slip occurred and its amplitude to compensate for its effect on the observation. Finally, the proposed system model and algorithm are validated by simulation.

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Carrier Phase Measurement in IRNSS using Antenna swapping Method

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.c4446.098319 ◽

2019 ◽

Vol 8 (3) ◽

pp. 1685-1688

Keyword(s):

Carrier Frequency ◽

Carrier Phase ◽

Phase Measurement ◽

Satellite System ◽

Space Research ◽

Integer Ambiguity ◽

Navigation Satellite ◽

Carrier Phase Measurement ◽

Accurate Position

Indian has been established its regional navigational satellite system i.e., IRNSS (Indian space research navigation satellite system). It is launched successfully with seven satellites. It provide accurate position to user in Indian and up to 1500km around the India. In this paper, calculated the integer ambiguity (N) which is one of the parameter of the carrier phase measurement. Carrier phase measurement is measure the range between the satellite and receiver expressed units of cycle of the carrier frequency.

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Improving the Performance of INS/GNSS System Using the Approach of Carrier Phase Measurements

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.21.172 ◽

2015 ◽

Vol 21 ◽

pp. 172-183

Author(s):

Badshah Khan ◽

Yong Yuan Qin

Keyword(s):

Carrier Phase ◽

Closed Loop ◽

Position Estimation ◽

Integrated System ◽

Integer Ambiguity ◽

Gps Receiver ◽

Position Measurement ◽

Phase Measurements ◽

Simulation Results ◽

Lever Arm Effect

This paper discusses the techniques of attitude, velocity ad position estimation from GNSS carrier phase measurements, and investigates the performance of the lower precision MEMS based INS/GNSS system based on carrier phase measurements. Generally, a GPS receiver estimates the position and velocity from code phase and Doppler measurements. Double differenced carrier phase measurements provide more accurate velocity and position estimation compared to code and Doppler measurements. However, for position measurement, the integer ambiguity is required to be removed. Multiples antennae approach is used to derive the attitude information from carrier phase measurements in order to control the large initial misalignment angles for initialization of the integration process or to utilize during benign dynamics. Lever arm effect is considered to compensate for the separation of GNSS antenna and IMU location. The derived three GNSS observables are used to correct the INS through optimal Kalman filtering in a closed loop. Simulation results indicates the effectiveness of the integrated system for airborne as well as for land navigation vehicles.

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Initial Assessment of the LEO Based Navigation Signal Augmentation System from Luojia-1A Satellite

Sensors ◽

10.3390/s18113919 ◽

2018 ◽

Vol 18 (11) ◽

pp. 3919 ◽

Cited By ~ 13

Author(s):

Lei Wang ◽

Ruizhi Chen ◽

Deren Li ◽

Guo Zhang ◽

Xin Shen ◽

...

Keyword(s):

Carrier Phase ◽

Phase Measurement ◽

Global Navigation Satellite Systems ◽

Initial Assessment ◽

Dual Frequency ◽

Carrier Phase Measurement ◽

Phase Measurements ◽

Satellite Systems ◽

Navigation Signal ◽

Global Navigation Satellite

A low Earth orbiter (LEO)-based navigation signal augmentation system is considered as a complementary of current global navigation satellite systems (GNSS), which can accelerate precise positioning convergence, strengthen the signal power, and improve signal quality. Wuhan University is dedicated to LEO-based navigation signal augmentation research and launched one scientific experimental satellite named Luojia-1A. The satellite is capable of broadcasting dual-frequency band ranging signals over China. The initial performance of the Luojia-1A satellite navigation augmentation system is assessed in this study. The ground tests indicate that the phase noise of the oscillator is sufficiently low to support the intended applications. The field ranging tests achieve 2.6 m and 0.013 m ranging precision for the pseudorange and carrier phase measurements, respectively. The in-orbit test shows that the internal precision of the ephemeris is approximate 0.1 m and the clock stability is 3 × 10−10. The pseudorange and carrier phase measurement noise evaluated from the geometry-free combination is about 3.3 m and 1.8 cm. Overall, the Luojia-1A navigation augmentation system is capable of providing useable LEO navigation augmentation signals with the empirical user equivalent ranging error (UERE) no worse than 3.6 m, which can be integrated with existing GNSS to improve the real-time navigation performance.

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The performance of bds relative positioning usage with real observation data

Boletim de Ciências Geodésicas ◽

10.1590/s1982-21702014000200014 ◽

2014 ◽

Vol 20 (2) ◽

pp. 223-236 ◽

Cited By ~ 1

Author(s):

Xu Tang ◽

Xiufeng He ◽

Samuel A. Andam-Akorful

Keyword(s):

Carrier Phase ◽

Phase Measurement ◽

Observation Data ◽

Relative Positioning ◽

Carrier Phase Measurement ◽

Phase Measurements ◽

Short Baselines ◽

Better Than

With the first phase of COMPASS/BeiDou-2 (BDS) completed, the assessment of positioning performance and the characterization of its system are analyzed and presented. Pseudo-range and carrier phase measurements modulated on B1 and B2 have been collected in Shanghai, from 00:00 to 24:00 on 28 December, 2012. Compared with GPS, visibility and measurement quality of BDS's GEO, IGSO and MEO satellites are analyzed. DOP during the whole orbital period is also analyzed the results demonstrate that BDS's HDOP is better than GPS's one, but VDOP opposite. Furthermore, the result of positioning is also presented and analyzed. Short baselines are estimated by standalone BDS and GPS's carrier phase measurement, respectively, using 48 segmentations of observations during a whole day (24 hours, each segmentation, is about 30 minutes observation). The analysis of static relative positioning demonstrates that BDS could achieve to millimeter level, corresponding to GPS. Kinematic result is produced by double differenced carrier phase observations with the ambiguities fixed under the constraint of precise short baseline.The result shows that the centimeter accuracy could be achieved. When comparing the results of kinematic baseline solutions, performance of BDS is worse than GPS on North and Up components, but oppositely on the component of East in the kinematic baseline processing.

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An Innovative High-Precision Scheme for a GPS/MEMS-SINS Ultra-Tight Integrated System

Sensors ◽

10.3390/s19102291 ◽

2019 ◽

Vol 19 (10) ◽

pp. 2291

Author(s):

Qunsheng Li ◽

Yan Zhao

Keyword(s):

High Precision ◽

Carrier Phase ◽

Integrated System ◽

Integration Scheme ◽

Tracking Loop ◽

Phase Measurements ◽

Gps Measurement ◽

Global Positioning ◽

Navigation Accuracy ◽

Tight Integration

The Doppler-assisted error provided by a low-precision microelectromechanical system (MEMS) strapdown inertial navigation system (SINS) increases rapidly. Therefore, the bandwidth of the tracking loop for a global positioning system (GPS)/MEMS-SINS ultra-tight integration system is too narrow to track Doppler shift. GPS measurement error is correlated with the MEMS-SINS velocity error when the Doppler-assisted error exists, leading to tracking loop lock loss. The estimated precision of the integrated Kalman filter (IKF) also decreases. Even the integrated system becomes unstable. To solve this problem, an innovative GPS/MEMS-SINS ultra-tight integration scheme based on using high-precision carrier phase measurements as the IKF measurements is proposed in this study. By assisting the tracking loop with time-differenced carrier phase (TDCP) velocity, the carrier loop noise bandwidth and code correlator spacing are reduced. The tracking accuracies of the carrier and code are increased. The navigation accuracy of GPS/MEMS-SINS ultra-tight integration is further improved.

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A Low-Cost, High-Precision Vehicle Navigation System for Deep Urban Multipath Environment Using TDCP Measurements

Sensors ◽

10.3390/s20113254 ◽

2020 ◽

Vol 20 (11) ◽

pp. 3254 ◽

Cited By ~ 1

Author(s):

Jungbeom Kim ◽

Minhuck Park ◽

Yonghwan Bae ◽

O-Jong Kim ◽

Donguk Kim ◽

...

Keyword(s):

High Precision ◽

Navigation System ◽

Carrier Phase ◽

Low Cost ◽

Integer Ambiguity ◽

Single Frequency ◽

Vehicle Navigation ◽

Phase Measurements ◽

Vehicle Navigation System ◽

Multipath Errors

In this study, we developed a low-cost, high-precision vehicle navigation system for deep urban multipath environments using time-differenced carrier phase (TDCP) measurements. Although many studies are being conducted to navigate autonomous vehicles using the global positioning system (GPS), it is difficult to obtain accurate navigation solutions due to multipath errors in urban environments. Low-cost GPS receivers that determine the solution based on pseudorange measurements are vulnerable to multipath errors. We used carrier phase measurements that are more robust for multipath errors. Without correction information from reference stations, the limited information of a low-cost, single-frequency receiver makes it difficult to quickly and accurately determine integer ambiguity of carrier phase measurements. We used TDCP measurements to eliminate the need to determine integer ambiguity that is time-invariant and we combined TDCP-based GPS with an inertial navigation system to overcome deep urban multipath environments. Furthermore, we considered a cycle slip algorithm for its accuracy and a multi-constellation navigation system for its availability. The results of dynamic field tests in a deep urban area indicated that it could achieve horizontal accuracy of at the submeter level.

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